BMW E46 Racecar - Project Car Part 3 - Elbow-Deep In The Guts

We left off in the E46 Racecar project series with pro skateboarder Rune Glifberg's 2003 BMW M3 receiving an six-point chrome-moly rollcage, fully fabricated and welded together by the metal artisans at Evosport in Huntington Beach, Calif. This was an important step in terms of race chassis prep, and quite possibly the most important safety system the car will receive. Now it's time to look at performance upgrades.

We'll start with the body mods. The great thing about this E46 is that it will be a dedicated track toy, so no purely cosmetic modifications (aside from the screaming orange cockpit and blacked-out fender gills and kidney grilles) need apply. By completely stripping the interior of all the unnecessaries-upholstery, back seat, carpet-this E46 already weighs significantly less than it did when it rolled off the dealer lot.

Even more weight savings couldn't be a bad thing. Evosport first punched out the factory roof panel and sunroof assembly and replaced it with a pure carbon fiber panel supplied by Vorsteiner. The new roof weighs just 6.5 pounds, saving around 40 pounds alone over the factory section.

The trunklid was replaced in similar fashion with a Vorsteiner V-CSL carbon piece. Vorsteiner offers a dry vacuum woven plastic (DVWP) unit, but this is the more expensive piece, full carbon on both the top and bottom, for estimated weight savings of 17 pounds. The hood was replaced with a Vorsteiner VRS Vented GTR panel, DVWP with carbon fiber vents (20 pounds lighter than stock). Finally, the glass rear window was knocked out and the gap sealed up with a Lexan panel, also sourced by Evosport, for a further 20-pound savings.

All told, the body panel replacements shed nearly a hundred pounds. The car tips the scales now at just under 2,900 pounds, so including what was pulled out of the interior, this E46 is about 500 pounds lighter than its factory weight-and that includes the six-point cage and the Sparco racing buckets bolted into the forward seating positions.

Speaking of those, the seats themselves are a Sparco Pro ADV on the driver side and a Sparco Pro 2000 on the passenger side, utilizing Evosport billet aluminum floor mount adapters. Both are fitted with Sparco harnesses. The quick-release steering wheel is a Sparco Mugello.

The stock shifter assembly was replaced with a unit from AutoSolutions, called the Ultimate Kit. Evosport likes it because it includes a lower carrier arm engineered to maintain proper transmission input rod alignment, using the same input angle as the factory system, to prevent premature wear on the transmission.

Chassis prep continued underneath the car with a full complement of proprietary Evosport and Evosport-recommended underpinning upgrades. First, to negate any inherent flex in the drivetrain connection points and essentially hardwire the system into the chassis itself, the squishy factory mounting bushings were replaced with solid metal units. These include a three-piece Evosport aluminum differential set and aluminum Evosport engine and transmission mount kit (four pieces, black anodized).

Likewise with the suspension. Solid rear shock mounts were procured from Ground Control, along with a rear arm "street stability" kit, which uses metal shims to shore up the rear trailing arm bushings and prevent excess travel to keep rear-wheel toe in line and optimize the tire contact patch to the drive wheels. Evosport adjustable rear lower control arms were added to enable rear camber adjustment and further dial in the suspension. Up front, Ground Control lower control arm bearings were added to, again, negate flex found in the factory units.

When Rune bought the car, it was already wearing an adjustable track suspension, but the components were badly worn. Springs and dampers were subsequently replaced with H&R RSS coilovers. According to Evosport's Brad Otoupalik, this suspension is not adjustable, but for the entry level racer, that's usually a good thing.

"Adjustability can prove problematic for the amateur racer," he says. "It's too easy to adjust settings beyond the correct parameters. We have a lot of experience with the H&R kit. The spring rates, shock rebound, and damping are all mated to each other." This allows the entry-level driver to focus more on improving his skills and familiarizing himself with his car than on trying to mix and match a proper suspension setup. The H&R RSS has been tuned and optimized by actual German race engineers, which most of us are not, and development took place on the Nürburgring.

H&R upper front camber plates were also added for front camber adjustments for optimal front-wheel bite on braking and turn-in, as well as an H&R antiroll bar installed for much the same reason. The factory rear bar was removed entirely to improve the independent rear suspension's compliance and to optimize contact patch at the drive wheels for powering out of corners.

For track wheels, Evosport generally recommends Enkei NT03+M cast alloys because they offer an ideal combination of strength, low overall weight (20 pounds for a 10x18, which is what resides in all four of this car's wheel wells), and affordability (each costs about $300). They're bolted to the hubs using H&R studs for greater reliability under racetrack stresses, and for ease of changing wheels. As far as rubber, Glifberg cut his racing teeth on Continental ContiSportContact 3 street tires. As he gets more serious and starts moving into competition settings like time attack events, he'll switch to Hoosier R-compounds.

Under the vented Vorsteiner hood, the S54 straight six remains naturally aspirated but subject to an array of performance mods filed under Evosport's Evo II power package, designed to take the S54's output from 275 wheel-hp to upwards of 305-a roughly 10 percent gain at the tires.

Induction is initiated with a Stage 1 AFE intake, the best system Evosport has tested for this application. On the engine's hot side, Evosport headers, mandrel-bent tubular units with pulse-tuned merge collectors, feed spent combustion gases into Evosport race midpipes that replace the factory catalysts.

Out on the fringes, Evosport Power Pulleys are installed to reduce parasitic accessory drag and include pulleys for the alternator, water, and power steering pumps. (A crank pulley is not included, as this can cause harmonics issues with the long S54 crankshaft and cause potentially extreme reliability faults.) Hardware mods are harmonized with software developed jointly between Evosport and Powerchip, which both optimizes performance and smooths drivability by re-plotting the S54 drive-by-wire throttle maps.

All power mods present on this car, with the exception of the midpipes (which your local smog station could take issue with), are Evosport-recommended even on a dedicated street car.

One upgrade not included as part of the Evo II package and one that could be considered overkill for the street, but one essential for frequent track use, is the Evosport Race Oil Cooling Kit. This was developed using Evosport's real-world race experience and frequent post-race engine oil analysis. The kit consists of an external oil cooler core, an adapter that allows replacement of the factory oil filter with an actual race filter (which is cleanable and reusable), and the Accusump failsafe, which monitors potential oil starvation conditions and can inject up to three quarts of oil into the system if such a condition is detected.

And there you have it-the entry-level optimized E46 racecar. As Rune becomes more comfortable both with the car and himself as a driver, he'll be using data acquisition tools in the form of a AIM MXL Pista data logger and digital display, and an AIM Smarty Cam to capture his on-track performance in real time. In the next project installment, we'll see exactly how one of these data-logging test sessions shakes out.

Bigger And Better Things
Evosport has announced the opening of its new state-of-the-art Performance Center in Huntington Beach, Calif. This move reinforces the company's continued growth and caps 10 years as an industry leader. The 15,000 sq. ft. center will house Evosport's multiple facilities under one roof, providing for performance product R&D, service and installation, and motorsport/racing support in one location. The new Performance Center will also allow Evosport to further focus on its Porsche brand programs in addition to its current specialty in BMW, Mercedes-Benz, and Ferrari vehicles. The company will be able to provide even greater value to its worldwide base of customers, expanding on the expertise of its factory-trained technicians and race engineers, advanced service and diagnostic equipment, engine building services, chassis and rollcage fabrication, wheel and tire service, street and track alignment service, dyno tuning, and more.

The Best Worlds?
It's an enduring dilemma for the trackday enthusiast, particularly the trackday enthusiast on a budget: having your fun on the racetrack while maintaining some sense of normalcy and comfort for everyday street driving.

Maybe it's because I'm getting old, but the one-car-fits-all mentality just doesn't seem that viable anymore. Whichever direction you move in-maintaining comfort or optimizing race performance-will inevitably compromise the other. The two are mutually exclusive, and it's really just impossible to do with a big degree of satisfaction, this having your cake and eating it too.

In terms of track-lapping prowess, there's small doubt Rune's E46 will stand headlights and shoulderline above just about any fully accoutered street M3, performance modifications be damned. There's just no contest. On the day of this shoot, Rune and Brad from Evosport staged an impromptu drag race between Project E46 and a modded E92-and the E46 pulled on the newer car. That was in a straight line. Clock the two back to back on the road course proper, and the ET discrepancies would likely be many seconds apart.

That said, you probably wouldn't want to drive Rune's racecar on the street-even though you legally could (he keeps it registered and fully insured). You wouldn't, if only for the fact that it takes about five minutes to negotiate the cage and settle into a seat, then strap yourself down with the five-pointers, and then don your helmet (so you don't crack your head open on the cage should a smash-up occur). Not to mention it's loud, most of the moving hard parts interfacing with each other in metal-on-metal terms, and there's no stereo or air conditioning.

No, the best of both worlds would indeed entail having two worlds-two cars, each dedicated to its own purpose. Particularly if you'd like to move beyond autocross or open track days and compete in an advanced (non-stock) racing class.

I pose the question: Which is the better platform for building a racecar?

"The E46," Otoupalik answers. "For all the following reasons: cost, weight, less complicated electronics, and the fact that all the aftermarket R&D has already been performed for this car. We've got an established recipe to work from."

I had a chance to take a squirt around a road course at the now-defunct El Toro airbase in Irvine, Calif., first in a bone-stock E92 M3. Then, while Rune was occupied with a TV crew, I snuck into his racecar and took a couple squirts in it.

The new M3 is an amazing car, easily one of my favorites, but much more refined than any of its predecessors. It keeps its driver more insulated, and thereby somewhat detached, from the driving experience. Like any car driven off the showroom floor, its potential performance edge has been dulled in order to appeal to the largest possible demographic. But for the street, it still makes a pretty good all-around package. Maybe even the best this side of a Porsche 911.

The raced-out E46, on the other hand, is now hardwired to the pavement and its driver in a way a showroom car never will be. Simply put, it is now a real racecar and must be treated as such. Coming off a 90-degree downhill turn, I underestimate the newly sharpened turn-in, cranking the wheel too hard toward the apex with probably a little bit too much throttle. The rear end comes around as I try, too late, to correct my mistake. I'm successful in straightening her out-but not before the ends swap places and I'm left gazing back at the corner that just kicked my ass. It's then that it registers: stability control on this car is completely disabled. As it should be.

Subsequent laps see me going a lot less cavalier and exercising a lot more patience-less testosterone in the throttle, more thoughtful, measured steering inputs. The rear end remains squirrelly, indicating I've been spoiled by DSC for far too long. When you anticipate the squirrels, they're easily corrected, and seat time makes all the difference. When you get really comfortable-which will still take me a couple hundred more laps in this car-it's possible to maintain tire-shredding drifts around some of the more extreme-angle bends on the course.

It's liable to bite you in the ass, as I quickly learned. But horsing it around the road course, it also becomes clear this car has been made into an exceptional learning tool. It asks a lot more from its driver than a stock car would, but that's kind of the point.

After I'm done bombing the circuit and killing cones, I jump in the passenger seat for some hot laps with Rune. He's quick to offer a disclaimer: "It's been a while since I drove this course and they changed the layout today." But his confidence with the car is evident, and it's immediately clear he's going seconds faster than I was.